Speed control mechanism



July 13, 1943., BQWERS 2,324,191

SPEED CONTROL MECHANISM Filed Oct. 2., 1941 5 Sheets-Sheet l INVENTOR.

fiflROLD A B0 WERS Wad/2% Attarncy Jufiy 13, 1943. H. A. BOWERS SPEED CONTROL MECHANISM Filed Oct. 2, 1941 3 Sheets-Sheet 2 lib GU U

INVENTOR. HARoLo A. BO ER5 Ateorne July 13, 1943. BOWERS 2,324,191

SPEED CONTROL MECHANISM Filed Oct. 2, 1941 3 Sheets-Sheet 3 INVENTOR. finRaLu A. Bowms Patented July 13, 1943 UNITED STATES PATENT OFFICE SPEED CONTROL MECHANISM Harold A. Bowers, Cincinnati, Ohio Application October 2, 1941, Serial No. 413,284

16 Claims.

This invention relates to a speed control mechanism for internal combustion engines when employed as a motive power for automobiles, buses, trucks and the like.

One of the principal objects of this invention is the provision of means which will enable a vehicle to operate at a desired or predetermined speed without the necessity of the operator watching a visible speed indicator, such as a speedometer, thereby permitting the operator to devote his entire attention to the road and promoting safe driving.

Another object of this invention is the provision of a mechanism which while useful in assisting in maintaining a predetermined definite speed, may, at will, be manually operated beyond its adjustment for a definite speed but will not change said speed adjustment wherefore the operator my return to said predetermined adjusted speed at will, for example, after an emergency which necessitated the increased or decreased speed.

A still further object of this invention is the provision of means that will definitely indicate to the operator of a vehicle that he is traveling at his predetermined maximum speed but which indicator may be arranged to operate at any other maximum speed he may select.

It is also an object of the present invention to provide means which will substantially maintain 7" constant the amount of fuel being supplied to the engine to thereby limit and maintain a predetermined desired speed of travel and economize on the fuel used.

It is also an object of this invention to provide a mechanism which will accomplish the above objects and at the same time provide means for resting the operator while driving since the supplying of fuel to the motor will require substantially no physical effort on his part to travel at the predetermined speed.

Other objects and advantages of the present invention should be readily apparent by reference "to the following specification considered in conjunction with the accompanying drawings forming a part thereof, and it is to be understood that any modification may be made in the exact structural details there shown and described, within the scope of the appended claims, without departing from or exceeding the spirit of the inventicn.

In the drawings:

Fig. 1 is a semi-diagrammatic view of the mech- 2.15m of this invention.

it I) Fig. 2 is an enlarged sectional view taken on line 22 on Fig, 1.

Fig. 3 is a transverse sectional view taken on line 33 on Fig. 2,

Fig. 4 is an enlarged fragmentary elevational view of a part of the mechanism as seen from line 44 on Fig. 1.

Fig. 5 is an enlarged vertical sectional view through a part of the mechanism taken on line -55 on Fig. 1.

view through a further portion of the mechanism.

Fig. 12 is a vertical sectional View through certain of the parts of the mechanism taken on line l2-I2 on Fig. 11.

Fig. 13 is a transverse sectional view taken through a plane behind that of Fig. 12 on line l3l3 on Fig. 11.

Fig. 14 is a fragmentary sectional view taken on line |4l4 on Fig. 11,

Fig. 15 is a diagrammatic view showing a simplification or modification of the mechanism of this invention.

Throughout the several views of the drawings similar reference characters are employed to denote the same or similar parts.

As was mentioned above, this mechanism per- .tains to a speed control means for self-propelled vehicles such as trucks, buses, pleasure cars, and the like. Each of these vehicles today has a selfpropelled engine to which fuel is supplied in varying quantities depending upon the desired rate of speed to be traveled. The fuel supply is generally under the control of a foot pedal mounted on the floor of the vehicle and operated by the drivers foot by being depressed when a higher rate of speed than that being traveled is desired. A reverse movement or operation of the foot pedal results in slowing down of the rate of speed from that being presently traveled.

States, counties, and cities have different rates of legal speed that may be pursued in various sections and localities. In order for the operator to be within the legal limit it is necessary for him to watch the visible speed indicator or speedometer and arrange his foot pedal accordingly. This positioning of the foot may be quite tiring or the road conditions may be such that the speedometer is not being carefully watched and the legal speed limit exceeded, or the road conditions may be quite favorable and the operator unconsciously exceeds the established legal speed limit.

By the present invention the operator is consciously checked from exceeding the speed limit at which he desires to travel yet he may, in the case of an emergency, exceed this limit during the time of emergency and then automatically return to the limit which he has established as his top speed; he of course can at any time operate below his desired top speed. These operations are accomplished in substantially the same manner in which they were previously accomplished, namely, through the use of a lever under the control of the operators foot or under the control of the hand lever, generally mechanically connected with the foot lever. At the same time, with the vehicle traveling at the desired top speed the operators foot is maintained in a restful position, without any appreciable conscious effort on his part, at which position the desired speed is maintained.

Specifically, and referring to the drawings, there is illustrated in Fig. 1 a vehicle floor board 20, dash board 2| and inclined connecting board or plate 22. The portions of the vehicle just described are normally located immediately below and in front of the operators seat or position and located there, also, is the foot pedal 23 hingedly connected at 24 to the inclined floor board or plate 22. Below the foot pedal 23 there is projecting a link 25 which passes through a suitable aperture formed in the floor board 22. The inner end of the link 25 is connected to one end of an arm 26 of a bell crank 2'! which is pivotally mounted in a bracket 28 projecting downwardly from the floor board 22. The second arm 23 of the bell crank 2'1 has pivotally connected to it one end of link 33 which has its other end pivotally connected to an arm 3| of the fuel supply valve 32a such as is associated withthe usual carburetor 32. The carburetor, as is well known, supplies the. intake manifold of the engine, and the amount so supplied determines the rate of rotation of the engine all of which is well understood and forms no part of the present invention.

It is further understood that depression of the pedal 23, or a counter-clockwise movement thereof about the hinge 24, causes an increased flow of fuel and therefore an increased speed of the engine. This operation of the foot pedal 23 is effected against the resistance of a spring 33 which has one end connected to the valve arm 3| and the other end anchored to a fixed part of the vehicle.

- Operated by the engine 389 through any suitable or desirable means, such as the belt 3M, pulley 4B, belt 332 and pulley 353, is a pump 34 for circulating oil which may be used for lubricating the various parts of the engine, operating the brakes, or other purposes, and which pump generally maintains the said oil at a given pressure. The source of supply for the oil is a sump, tank or the like generally located below the engine and diagrammatically shown at 35 in Fig. 1., Extending from the pump 34 is an intake pipe 35which has its other end located in the III sump or pan 35 and may be supplied with a screen, filter or other purifying mechanism, not shown. Extending from the other side of the pump 34 is the delivery or pressure pipe or conduit 3! terminating, as mentioned above, at the engine for lubricating purposes, or brake cylinders, or the like, none of which is shown as they form no part in the present invention.

Associated with the engine is, generally, an externally driven part, such as, an electric generator 38 provided with a shaft 39 having a pulley 4!] for either a belt, a chain, or the like, and driven at the same speed as, or at a speed definitely proportioned to, the speed of the engine. It will be understood that instead of the generator 38, or other part so supplied with vehicles to be so operated, a specific shaft may be supplied to be operated from the engine at a speed definitely proportioned thereto for the purpose of operating the mechanism of this invention, as will later be made clear. Such other part generally supplied with vehicles, and in some instances preferable for the purpose of this invention, is the drive shaft to the driving wheels, speedometer cable, or other member, which has a speed of rotation that is generally more directly proportioned to the speed of travel of the vehicle than to the speed of rotation of the engine, since there is generally provided a set of change gears between the engine and drive shaft and the speedometer cable, and which parts are not shown in the drawings since they are well known.

The mechanism of this invention comprises three principal members, the stop device 4|, the actuating pressure developing device 42, hereinafter referred to as a generator, and the actuating pressure selecting device 43.

The actuating pressure developing device, or generator 42, is shown in one structural form in Figs. 11 to 14, inclusive, and comprises a housing member 44 having a circular chamber 45 at one end thereof and closed by closure plate 46. Extending from the chamber 45 is a bore 4'! closed at its outer end by a plate 48 and intermediate bearing supporting member 49. The bearing supporting member 49 and closure plate 48 are each provided with an anti-friction bearing 50 for supporting, for rotation, a shaft 5|. Encircling the shaft 5| and journaled in the housing bore 41 is a sleeve 52 having at its one end, and within the chamber 45, a radial flange or rotor 53, said sleeve 52 and rotor 53 keyed to the shaft 5| for rotation thereby. The rotor 53 has considerable thickness and houses the valves for determining or generating the operating pressure. As seen in Figs. 11 and 12 the rotor 53 is provided with a transverse bore 54 in which, on each side of the shaft 5|, is secured a valve bushing 55 and 56. The valve bushings, in turn, respectively enclose a piston valve 51 and 58.

The valve bushings and their enclosed valves are substantially identical in construction, except for weight and diameter as will be subsequently pointed out, wherefore it is deemed sufficient if but one of them be described in detail. Accordingly, valve bushing 55 is provided with a plurality of sets of radial ports, 59, and 6|, each set being encircled by a similar circumferential groove 52 formed in the exterior of the bushing 55. The bushing 55 is provided at its inner end with an enlarged bore 63 which terminates at a shoulder 64 from which a smaller bore 65 extends at the other end of the bushing. The piston valve 51, within the bushing bore 53-65, is provided with piston portions 65 and 61, each of a diameter closely simulating that; ofits bore, and said piston portions are connected by a reduced portion 68. It will be noted that the inner ends of the bushings 55 and 56 terminate on or substantially adjacent thesurface of the shaft thereby providing between them a chamber 63, see Fig. 14. Each. of the piston valves 57 and 58, is provided centrally with a bore I and 'II thereby effecting communication, through said piston valves, between the ends of the bushings, the chamber 45 and the chamber 63, the purpose of which will be explained later.

Behind the bore 5.4, the rotor 53 is provided with a port I2, located to one side of the shaft I, and ports 'I3.and 14, located in a plane including the center or axis of the shaft and are respectively drilled from the opposite sides of the flange 55 toward one another terminating however short of said shaft. The port I2 has communicating with it, near its opposite ends, ports 75 and 13 which terminate respectively with the ports 53 of valve bushings 55' and 56. Communicating also with the port I2 is one end of a port H which extends through the sleeve 52 and parallel with the axis thereof. A transverse port 18in the sleeve 13 connects the port ll with a groove formed around the exterior of the sleeve 52. The groove 79 in turn is connected through a port in the housing 44 with a pipe fitting 80 which carries one end of a pipe SI extending from th pump pressure pipe 3?.

From'the foregoing it will be noted that pressure is connected with the outer ports of each piston valve 51 and 58 to enter the space between the valve piston portions 65 and El.

The port 73, similar to port 12, has communicating with it one end of a transverse port 82 which communicates, on its inner end, with the valve bushing ports 60 of valve bushing 55. Also communicating with the port 13 is one end of a port 83 extending longitudinally of the sleeve parallel with the port 11, but angularly spaced therefrom. The port 03 communicates through a port 8 with a pipe fitting 85 carrying one end of a pipe 86 whichv has its other end connected to the actuating pressure selector device 43.

The port M, similar-to port I3, is connected through a transverse port 6.1 with the bushing ports 60 of valve bushing 55and, again similarv to port I3, has connected therewith one endof a port83 extending longitudinally of the sleeve 52 parallel with ports I! and 83 but angularly spaced therefrom. A radial port 09 in the sleeve 52 connects the port 88 with a pipe fitting 90 which carries one end of a pipe or conduit 9| whose other end terminates in the actuating pressure selecting device 43.

A pipe fitting 92 carried by the housing M con nects the chamber 45 by way of a port 93 with one end of, avpipe 33, carried by the fitting 32, with the sump or oil pan 35. The sets of ports iii, through their circumferential groove connect with the chamber 89, between the bushings and 58, by way of vertical ports 95 in the outer surface of saidv bushings. There is also provided in the sleeve 52, a port 96 which extends longitudinally thereof and connects at its opposite ends the chamber 59 and the space of the bore 4'! at the inner end of said sleeve 52, thereby connecting any leakage longitudinally of the. sleeve 52 with the chamber 63. This chamber 69 communicates by way of the bores or;

, maintain the groove ports F0 and II: in the valves 5'! and. 58 with the chamber 45 and therefore the pipe or conduit 94 and sump or oil pan 35..

The actuating pressure selecting devce, in its preferred form, is illustrated structurally in Figs. 5 to 10, inclusive, and comprises three housing members, an upper housing member 91, intermediate housing member 98 and a lower housing member 99 suitably bolted to one another to form a unitary structure. The upper housingv member is provided with a bore I08, the opposite ends of which are closed by end caps IN and I32. Disposed within said bore is a bushing I03 keyed or otherwise fixed against rotativemovement. The bushing I03 is provided. substantially centrally, of its length with a plurality of radial ports, shown in the drawings as six in.- number and identified. by reference characters I94, I05, I05, I01; I08 and I39. These radial ports are at all times in alignment with vertical bores or ports formed through the housing 91 and identified by reference numerals H3, III, H2, H3, H4 and H5. It should be here noted that the number'of. radial bores ISA-I03 in the bushing I03. may be increased or decreased depending entirely upon the range desired in the mechanism and that the number of ports I I0I I5 will be correspondingly changed.

Mounted within the bushing I03 is a rotary valve member H6 having projecting from one end thereof a shaft I I! which passes through the end cap member I02 and also passes through the panel H8 of the vehicle body. The rotary valve member I I 5 is provided at spaced points along its length with circumferential grooves I I9, I2I, I22, I23, and I24 and substantially semi-circumferential groove I20; with the grooves I20 and I2I connected by a pair of spaced longitudinal grooves I25, and with a pair of grooves I26 and I2! extending longitudinally of the valve H6 for a distance from the circumferential groove I23 toward the circumferential groove I22 but without conmeeting said grooves. A transverse port I28 connects the circumferential groove II9 with a port I 29 disposed centrally longitudinally of the valve member H6. As shown in Fig. 9 the semi-circumferential groove-I20 is adapted to be in communication with either of two ports I30 and I3I formed radial of the bushing I 03' and which ports at their outer ends communicate, respectively; with chambers I32 and I33 formed by inclined cut-away portions on the bushing I 03. It is with these chambers I32 and I33 that pipe fittings I34 and I 35 respectively communicate and which pipe fittings respectively carry the pipes or conduits 9i and from the actuating pressure developing mechanism 42. port I30 or I3I, depending upon which one the groove I20 is in communication with, is transmitted by the longitudinal groove I25 to the circumferential groove I2I. The pressure fluid is then connected by the groove I 2| with a radial port I36 in the bushing I03 and thereby with a longitudinal port I31 formed for a portion of the length of the bushing I03 intermediate its ends at its lowermost point. The bushing port I3! connects with a pair of ports I38 and I39, formed vertically of the housing 91, and a pair of transverse grooves I40 and MI for a purpose later to be made clear.

The longitudinal ports or grooves I26 and I2! are adapted to be respectively brought 'nto alignment in successive order with the bushing radial ports I04- I09. In order to accurately align and I23 or I 21 with the radial The pressure fluid in the.

ports I04--I09 the valve H6 is provided at its forward end with a radial flange or collar I42 having a plurality of detent seats I43 formed therein for cooperation with the spring pressed detent I44 carried by the adjacent end of the bushing I03. The rotation of the valve H6 is accomplished by a knob or the like I45 on the end of the valve shaft H1.

The intermediate housing 98 of the control pressure selector valve mechanism is provided with a plurality of valve bores I46, I41, I48, I49, I and I5I each housing a valve mechanism, each of which is substantially identical in construction and identified in general by the reference numeral I52. One valve mechanism I52 is shown in structural detail in Fig. 7 and since each of them is substantially identical, it is deemed sufiicient if but one of them be described in detail.

By reference to Fig. '1, it will be noted that the valve mechanism I52 comprises a valve bushing I53 through which is formed a plurality of sets of radial ports I54, I55 and I56 each set of ports being encircled by a similar circumferential groove I51 formed in the exterior of the bushing I53. It should be noted that the valve bushing I53 substantially takes up the entire height of the housing 98 and has its upper end engaging the lower surface of the housing 91 and its lower end engaging the upper surface of the housing 99. Each of the bushings I53 is provided in its upper end with a bore I58 terminating in the shoulder I59 from which a smaller bore I60 extends to the other end of the bushing. Disposed in said bushing bore I58--I60 is a piston type valve having the piston portion I6I at its upper end, a piston portion I62 at its lower end and a reduced portion I63 connecting said piston portions.

Formed vertically of the intermediate housing 98 but not extending entirely therethrough is a series of ports I64, I65, I66, I61, I68 and I69 which respectively communicate at their upper ends with a vertical port IIO-I I5 inclusive formed in the upper housing 91. Each of these ports I64I69 is respectively in communication with a transverse port I10, I1I, I12, I13, I14 and I15 which in turn respectively communicates with the radial ports I55 of a valve mechanism I52 in the valve bores I46I 5 I, see Fig. 6. The radial ports I54 of each valve mechanism I52 are inter-connected by ports I16 which terminate in a pipe fitting I11 carrying one end of a pipe or conduit I18 that terminates in the sump or oil pan 35. Ihe ports I56 of each valve bushing are likewiseinter-connected by means of ports I19 which terminates in a pipe fitting I80 carrying one end of pipe or conduit I8I which is a branch of the pressure pipes or conduits 8| and 31.

The lower housing 99 of the control pressure selecting device is provided with a counter-bore I82 beneath each valve mechanism I52 into which the lower end of the valve piston I62 may project. Each of these valve pistons is hollow for a portion of its length into which projects one end of a spring I83, the other end of which abuts with the upper end of an adjusting screw I84 threaded through the housing 99 and axially aligned with the piston valve. It will be appreciated that each piston valve has its own adjusting screw I84, whereby the loading of each valve spring I83 is individually determined and afiected. The end of the adjusting screw I84 is closed by a suitable cap I89 threaded onto the projecting end of the screw I84. It should be noted that the housing 99 is provided with a smaller diameter counter-bore I90 beneath each counter-bore I82 and that these counter-bores I90 are inter-connected with one another by ports I9I which terminate in a pocket I92 which is in communication with a vertical port I93, in the intermediate housing 98, a vertical port I94, in the upper housing 91, vertical port I95, in the bushing I03, and the space or bore of the bushing I03 between the end of the valve IIS and end cap IOI. This space is connected by a pipe fitting I96, which carries one end of a pipe I91 that communicates at its other end with the sump or oil pan 35.

It should be noted that transverse grooves or ports I40 and MI, formed in the lower surface of the housing 91, respectively communicate with valve bores I46, I41, and I48 and valve bores I49, I50 and I5I for actuating the piston valves therein for a purpose that will later be made clear.

Referring again to valve II6 its circumferential groove I23 is connected by a radial port I98, in the bushing I03, with a pipe fitting I99 which carries one end of a pipe 200 that terminates in the stop device 4I.

The stop device M is shown structurally in Figs. 2 and 3 and comprises a housing member 20I carrying a pipe fitting 202 which in turn carries the lower end of the pipe or conduit 200. The pipe fitting 202 communicates with a cylinder 203 of the housing 20I in which is mounted for sliding movement, a piston plunger 204. The piston 204 has secured to its lower end a plate 205 which has also secured to it one end of a metallic bellows 206 which has its other end permanently secured to the housing 20I. By this construction the metallic bellows 206 provides a chamber 201 interiorly thereof in which is disposed the cylinder 203 and the piston 294. The piston 204 is centrally bored as at 208 which communicates with the chamber 201 by a transverse port 209.

Projecting downwardly from the plate 205 is a clevis 2I0 having pivotally connected therewith a link 2I I, see Fig. 1, to Whose outer end is pivotally connected one end of a link 2I2 which has its other end permanently secured to the bell crank 21 so as to partake of any oscillatory movement imparted thereto by the foot pedal 23. As shown in the drawings the stop device housing 20I is bolted or otherwise secured to the inner surface of the dash board 2I.

The operation of this mechanism is as follows:

The engine (not shown) is started in the usual way and rotates at what is known as the idling speed, for rotating or driving the pump 34 and circulating the oil or other fluid at its established pressure in the pressure line 31 which, for example, may develope a pressure or approximately 45 pounds per square inch, and for the purpose of this invention may be referred to as the primary pressure. At the same time the engine drives the generator 38 or other shaft having thereon the pulley 40 which through the belt 2I3 and pulley 2I4 on the shaft 5I, rotates the said shaft 5| and the operating pressure developing member 5253.

The rotation of the pressure developing member 52-53 through centrifugal action throws the piston valves 51 and 58 outwardly against the oil pressure, thereby more or less opening the ports 59 of the bushings 55 and 56 to allow a pressure fiow lubricating oil through the said ports. This pressure flow through the said ports is from the pressure pipe 31 to pressure pipe 8|, fitting 80, circumferential groove 19, radial port I8, longitudinal port 11, radial port I2 and ports 15 and I6 to the space surrounding the reduced portions 68 of the valves 51 and 58. The pressure surrounding said piston valve reduced portion acts on the inner surface of larger piston valve portion 66 of said valves to counteract the outward throw thereof under centrifugal force, and co-operates with the centrifugal force in stabilizing the said piston valve at substantially a given position. The opening of the ports 59 effects a lesser or greater opening of the ports 6| by the piston portions 65, where-by a flow of fluid entering by way of ports 59 is returned to the sump or oil pan 35, and the greater the opening of the ports 59 and lesser the opening of ports GI, the greater the pressure around reduced portion 68. The flow from the ports GI is through ports 95, chamber 59, piston valve bores I and II, chamber 45, port 93, pipe fitting 92 and pipe or condut 94 to the sump 35. With the actuating pressure generator running at a given speed the ports 59 are opened to permit a certain amount of fluid fiow, and therefore develop or generate a given pressure in the space between pistons 66 and 61. As the speed of rotation of the member 52-53 is increased the piston valves 51 and 58 are accordingly urged away from the shaft 51 to open ports 59 and eiTect an increased pressure from the ports 59 to oppose the centrifugal outward urge of said pistons, thereby, effecting the said stabilizing of the piston valves at the higher speed. Decrease in speed relieves the outward urge on the piston valves whereupon the pressure acting on the piston portion 56 balances the piston valves at a point with a lesser opening of ports 59.

It should be noted at this time that the valve bushings 55 and 55 could have their radial ports 6| eliminated so that there would be no flow of fluid between these ports and the intake ports 59, Wherefor there will be only enough flow through the ports to supply the actuating pressure for outflow through the ports 55. Theoperation of such a device would be as described above.

The pressure surrounding the reduced piston portion 68 is connected to the operating pressure selecting device 93, and this flow from the valve bushing 55 is through ports 69 and 82, radial port I3, longitudinal port 83, radial port 84, pipe fitting 85 and pipe or conduit 85 to the pipe fitting I35. The flow from the bushing 56 is quite similar to that just described, and is by way of bushing radial ports 56, port 81, radial port I4, horizontal port 88, radial port 89, pipe fitting 98, pipe or conduit 9i and pipe fitting I34.

It will be seen that there is a differential or difference in weight between the piston valves 51 and 58, as well as a difference in area between the piston portions of said piston valves wherefore their position outwardly from the shaft at a given speed will be diiferent, or in other words the said piston valves would respectively occupy the same position to their respective ports at different speeds. This difierence, in one form of the invention, may be in the nature of a ratio of 2 to 1 in ultimate results. In other words with the selector mechanism utilizing a given selector valve, the control mechanism comes into operation with one of the pressure developing piston valves at a point 2 times the speed at which the same selector mechanism was in operation with the other control pressure developing piston, all as will be made clear shortly.

As illustrated in the drawings the particular pressure developing piston valve being employed is the high speed one, namely, piston valve 58 and the circuit controlled thereby. Accordingly the flow of the control pressure is, at this time, from the pipe fitting I34 to the chamber I32, radial port I38, semi-circumferential groove I20 of the rotary valve IIB, longitudinal groove I25, circumferential groove I 2| vertical port I 36, longitudinal port I31, vertical ports I38and I39 and transverse ports I45 and I'll. In other words this pressure is acting on each of the piston valves of each valve mechanism I52 for attempting to actuate said piston valves against their springs E83. As a matter of fact, the particular pressure therein will effectively operate only the piston valve which is adjusted for that particular pressure. As seen in Fig. 5 the selector valve HE is arranged to have its longitudinal groove I21 aligned with vertical ports II 0 and I64 which through the transverse port IIll is connected with the valve mechanism I52 in valve bore I5 I. With the parts in the position shown in the drawings it is the adjustment of the spring I83 of this Valve only that is controlling the speed of the vehicle.

As shown in Fig. 4 this speed is 35 miles an hour or the-position in the high speed range and the slowest speed capable of control by valve piston 58.

When the motor speed is suflicient to drive the vehicle at the select speed of 35 miles per hour, the pressure acting on the valve piston in the bore 5I actuates said piston to open the radial ports I56 and close the ports I 54. This adjustment of these parts controls a flow of the operating fluid from the pressure lines 3'11 and BI through the pressure line I3I, pipe fitting I80, cross ports I'IS, valve bushing ports I55, reduced portion I53 of the piston valve, ports I54, cross ports I76, pipe fitting ill, and pipe or conduit I78 to the sump or oil pan 35. It will be appreciated that the opening of the ports I 56 effects a flow therethrough to and through the ports I55 to the sump or pan 35, establishing a pressure around the piston ports I53. The pressure surrounding the piston valve reduced portion 563 flows through the ports I55, connecting port I75 in the housing 98, vertical ports I64 and Ill), bushing radial port I54, selector valve longitudinal port I27, selector valve circumferential groove I23, bushing radial port I58, pipe fitting I99, pipe or conduit 2% to the stop device ii. This pressure within the stop device acts on the piston 254 and its plate 255 for actuating it in a downward direction as seen in Figs, 1 and 2.

The pressure in the stop device is from pipe Zilil through pipe fitting 252, cylinder 203, piston plunger bore or port 268 and cross port 208. The pressure acting on the piston 2M and its plate 205 opposes through the linkage 2.I I-2I2, bell crank 21 and link 25 the further depression of the pedal 23.

With the parts in the positions set forth in the drawings, thereis no pressure acting on the pisten 20%, and its plate and the pedal 23 is in its normal or motor idling speed position. The operator, therefore, by placing his foot on the edal will. by its own weight, displace the pedal 23 and elevate the piston 284 and its plate 2 35 thereby opening the carburetor to speed up the rate of rotation of the engine. As the engine speed increases the speed of the control pressure member increases to displace the piston valves 51 and 58 and thereby increase the actuating pressure in the pipes or conduits 8G and SI and thereby increase the pressure acting on all of the selector mechanism pistons. As soon as the pressure reaches the point of overcoming the selected piston of the selector mechanism, in the example illustrated, the piston in the valve bore II, this piston valve is operated to connect the branch pressure line I8I with the piston plunger 204 and tend to stop further movement of the operators foot. As was mentioned above, this point is reached when the pedal 23 is in the position for operating the vehicle at the rate of mile per hour. If the operator decides to exceed this limit physical force will be necessary to overcome the pressure in the pipe 200 and backup the pressure in this line. This backing up pressure acts on the larger piston IBI to open ports I54 and connect to the sump. If the operator does not desire to exceed his selected speed, he upon reaching the point where physical force is necessary to increase his rate of travel, is automatically made aware of the fact that he is traveling at the speed which he desired, and instead of increasing his speed merely allows his foot to rest in a comfortable position on the pedal 23 with hi vehicle traveling at his desired maximum speed. In the event, however, an emergency arises requiring a greater speed, such as to pass another vehicle, he can readily do so by pushing forward on the pedal 23. Should it be desired to slow up the speed of the vehicle it is only necessary to slightly raise the foot whereupon the normal spring 33 will elevate the pedal.

When an up-grade in the road is encountered the vehicle normally slows down unless additiona1 fuel is supplied to the engine. Without the use of the speed control mechanism as disclosed herein, the operator consciousl depresses the pedal 23 to supply the additional fuel, not necessarily maintaining his desired speed. With the speed control mechanism maintaining the desired speed, however, this further depression of the pedal 23 results in no increase of vehicle speed. Thus there is no increase in the rate of rotation of the driving force to the shaft 5|, no increase in the centrifugal force acting upon the piston valves 51 and 58, no further opening of the ports 59 with a corresponding closing of the ports 6|, no increase in the pressure through the ports (it, so that no greater pressure acts upon the piston valves I52. The weight of the operators foot is thereby counterbalanced in a new position for up-grade travel at the selected speed. This operation of the mechanism takes place automatically wherefor, with the speed control mechanism functioning as disclosed herein, there is substantially no change in speed upon encountering an up-grade on which the engine is capable of maintaining the selected speed. When a nominal down grade is encountered, the reverse action takes place, the weight and momentum of the vehicle being added to the power supplied by the engine, with a resultant decrease in fuel demanded by the engine to maintain the desired speed. Were the operator to resist the urge of the stop pressure upon the pedal under these conditions, the speed of the vehicle and of the engine would be increased slightly with a resultant increase in the rate of rotation of the driving force to the shaft 5!. The centrifugal force acting upon the piston valves 57 and 58 would be greater and would balance these piston valves against a greater pressure upon their enlarged portions 66 due to their shifting toward a slightly greater opening of the ports 59 with a corresponding closing of the ports 6|. This au mented pressure through the ports 60 as previously explained, would act upon the piston valves I52 to further compress their spring I83. That valve whose spring is adjusted for the selected speed would shift slightly toward the position which would permit the flow of a higher pressure to the stop mechanism as previously explained, urging the pedal 23 toward a new position to decrease the fuel supply to the engine until the selected speed were resumed. However, since the operator is merely resting the weight of his foot upon the pedal $13, he will not resist the aforementioned upward urge upon it, but will merely allow the weight of his foot to be counterbalanced in a new position for down grade travel at the selected speed. This operation of the speed control mechanism may be said to take place automatically with the result that there is substantially no change in speed upon encountering a down grade on which the compression drag of the engine is sufiicient in braking power to prevent an increase in the vehicle speed.

It should be noted that each of the piston valves of each valve mechanism I52 is independently adjusted so as to provide the same pressure, when combined with the resistance of the spring 33, within the stop device M for resting or counterbalancing the weight of the operators foot when a given speed is reached. This speed as indicated on the control knob or dial in Fig, 4, for example, ranges from 35 to '75 miles per hour in the high speed range and from 14 to 30 miles per hour in the low speed range. As was pointed out above the high speed range i obtained through the generator piston valve 58 while the low speed range is obtained through the generator piston valve 51. These parts, as wa mentioned above, are to be so balanced that when the selector valve H5 has its groove I21 in alignment with either of the bushing radial ports I! and I99 inclusive this speed will be 2 /2 times greater than that obtained when the companion longitudinal port I26 is in alignment with the said radial ports Ill i to IE9 inclusive. In other words with the longitudinal port I2! connected with radial port I04 a speed of 35 miles per hour is controlling while if the longitudinal port I25 were in alignment with the radial port I04 a speed of 14 miles per hour would be controlling.

This is caused by the connection of the semicircumferential groove I20 with the radial port I3! of the bushing I03 and the chamber I33 with which the controlling pressure, a effected by the piston valve 58, is connected as above described. It is understood, of course, that these speeds are by way of example only and may be varied Within any desired range. It will also be understood that the ratio between the piston valves 51 and 58 may be changed upward or downward from 2 /2 to 1 thereby making the low limit and the high limit closer to or farther from one another, this being of course controlled primarily by whether the device is to be used on trucks, buses, or pleasure vehicles, or even other types of selfpropelled vehicles.

The foregoing description has dealt with a mechanism wherein the operator can select a speed within a given range and with the mechanism providing a high and a low speed range and a plurality of actuating or controlling pressures. The mechanism diagrammatically illustrated in Fig. 15 is a material simplification of,

the device and utilizes butone actuating-pressure developing piston valve such.- as 580;. delivering the pressure to but a single valve mechanism such as l52a from which the actuating-pressure.

is delivered to the stop mechanism 4L. In this.

case the operator may have the screw l84a arranged sov that he can-adjust the same while his vehicle is in motion and would adjust. it to. the.

speed to which he. desires to travel due to prevailing conditions. It will, of course, be under-- stood that the screw- I Macouldbe outofreach while driving, and would therefore act as a maximum speed limit, the. operator. operating the:

pedal 23in the normal manner'for speeds under his desired maximum; A-larger.' effective area in. the actuator-may be used to definitely prohibit. higher speeds. if required.-

Reference to pressure flow herein does not necessarily mean fluid flow; Static pressure may be: considered to flow by means of entering the same pressure through the ports, conduits, etc:

From the foregoing it will now be appreciated that there has been provided a speed control mechanism whichwill automatically indicate to the operator that he is traveling at' his safest speed of his own selection consistent with operating conditions, and that this speed can be maintained with a mininiumof effort on his part. At the same time he is given a warning when he reaches his speed limit although. he may ex-- ceed this limit if he so desires. This mechanism further provides for the comfort of the operator since his foot is in a restful position and" not under constant strainto maintain aspeed at orbelow the legal maximumspeed.

What is claimed is:

1. In a mechanism" of the class described the combination withan engine, a fuel supply mech anism, and a manually operable member for controlling the operation of the fuel supply mechanism operable through a given path of movement from a point'indicating minimum rateof movement of the vehicle to a point indicating maximum rate of movement of a vehicle, of a hydraulically operated stop for limiting the operation of the manually operable member when the vehicle speed reaches a predetermined maximum.

2. In a mechanism of the class described the combination with an engine, a fuel supply mechanism, and a manually operable member for controlling the operation of the fuel supply'mechanism to control the rate of operation of a vehicle, of a hydraulically operated stop forlimiting the operation of the manually operable member when the vehicle speed reaches a predetermined maximum, including means for generating a hydraulic pressure, a hydraulic system for said stop, and a valve operated by the generated pressure for connecting the hydraulic system with the stop.

3. In a mechanism of the class described the combination with means for feeding fuel to an engine, a manually operable member for controlling the operation of the fuel feeding means.

and means for circulating a fluid under pressure, of a hydraulic stop connectable with fluid under pressure for limiting the operation of the manually operable member, a valve operable for connecting the fluid under pressure with the stop, and means for effecting the operation of the valve.

4. In a mechanism of the class described the combination with means for feeding fuel to an engine, a manually operable member for controlling the operation of the fuel feeding means,

and'means -for circulating-.2; fluid under pressure,-

of ahydraulic stop connectablewith fluid under. pressure for limiting the operation of. the manually operable member, a valve operable for connecting the fluid under pressure with the stop and means for effecting the operation of the valve, saidvalve being yieldably adjustable whereby the hydraulic stop may be forcibly displaced. to permit movement of the manualmember beyond.

its normal stop position.

5. In amechanism of the class described the combinationwith means for feeding fuel to an.

engine, a manually-operable member for controlling the operation of the fuel feeding means, and means for circulating a fluidunder pressure; of. a hydraulic: stop connectable with fluid under pressure for limiting the operation of the manually operable member, avalve operable for con-- necting the fluid under pressure with the stop,

and means for effecting the operation of the and means for effecting the operation of the" valve, and said valve operating means being connected with the engine for energization thereby whereby said valve operating means is operated at a point consistent with the engine speed, and means for preadjusting the position of the valve for limiting the movement of the manually actuable lever and limiting the speed of the engine.

7. In a mechanism of the class described the combination with means'for feeding fuel to an engine, a manually operable member for controlling the operation of the fuel feeding means, and means for circulating a fluid under pressure, of a hydraulic stop connectable with fluid under pressure for limiting the operation of the manually operable member, a valve operable for connecting the fluid under pressure with the stop, means for effecting the operation of the valve,

said valve operating means being connected with the engine for energization thereby whereby said valve operating means is operated at a point consistent With the engine speed, and means for preadjusting the position of the valve for limiting the movement of the manually actuable lever and limiting the speed of the engine, said stop being. adapted to be physically displaced with respect to its effective position of adjustment to permit actuation of themanual member beyond its normal stop position and efiect an increase speed of rotation of the engine.

8; In a speed control mechanism for internal combustion engine driven vehicles the combination with a fuel supply device for the engine, a manually operable member for operating the fuel supply device, and a hydraulic system for circulating a hydraulic fluid under pressure, of means driven by said engine at a speed proportional to the speed of the vehicle driven by the engine and connected to the hydraulic system.

for generating a pressure proportional to the speed of the vehicle, a hydraulic stop operable by said control pressure generating mechanism for limiting the speed of the engine, and means to connect the hydraulic fluid under pressure and hydraulic stop when the generated pressure has reached a predetermined point with regard to the rate of speed of the vehicle.

9. In a speed control mechanism for internal combustion engine driven vehicles the combination with a fuel supply device for the engine, a manually operable member for operating the fuel supply device, and a hydraulic system for circulating a hydraulic fluid under pressure, of means driven by said engine at a speed proportional to the speed of the vehicle driven by the engine and connected to the hydraulic system for generating a pressure proportional to the speed of the vehicle, a hydraulic stop operable by said control pressure generating mechanism for limiting the speed of the engine, and means to connect the hydraulic fluid under pressure and hydraulic stop when the generated pressure has reached a predetermined point with regard to the rate of speed of the vehicle, said fluid pressure and stop connecting means including an adjustable valve for adjusting the point of generated pressure control of the stop, and means for adjusting said valve.

10. In a speed control mechanism for internal combustion engine driven vehicles the combination with a fuel supply device for the engine, a manually operable member for operating the fuel supply device, and a hydraulic system for circulating a hydraulic fluid under pressure, of means driven by said engine at a speed proportional to the speed of the vehicle driven by the engine and connected to the hydraulic system for generating a pressure proportional to the speed of the vehicle, a hydraulic stop operable by said control pressure generating mechanism for limiting the speed of the engine, and means to connect the hydraulic fluid under pressure and hydraulic stop when the generated pressure has reached a predetermined point with regard to the rate of speed of the vehicle, said fluid pressure and stop connecting means including an adjustable valve for adjusting the point of generated pressure control of the stop, and means for adjusting said valve, said stop being capable of displacement by physical force on the manually operable member whereby the hydraulic pressure on the stop is overcome.

11. In a speed control mechanism of the class described for internal combustion engines, the combination with a fuel supply device for controlling the rate of supply of fuel to the engine and therefore the rate of travel of a vehicle driven by the engine, a manually operable member for operating the fuel supply device, and a hydraulic system for circulating a hydraulic fluid under pressure, of means for determining the ultimate desired speed of the vehicle comprising a control pressure generator driven by the engine and connected with the hydraulic system for modifying the pressure therein to control use, a hydraulic stop operated by the hydraulic fluid under pressure for limiting the operation of the manual member and therefore the operation of the fuel supply device, and means operated by the control pressure generator for selectively connecting the hydraulic pressure with said stop whereby said stop is effective upon the vehicle reaching a predetermined speed.

12. In a speed control mechanism of the class described for internal combustion engines, the combination with a fuel supply device for controlling the rate of supply of fuel to the engine and therefore the rate of travel of a vehicle driven by the engine, a manually operable member for operating the fuel supply device, and a hydraulic system for circulating a hydraulic fluid under pressure, of means for determining the ultimate desired speed of the vehicle comprising a control pressure generator driven by the engine and connected with the hydraulic system for modifying the pressure therein to control use, a hydraulic stop operated by the hydraulic fluid under pressure for limiting the operation of the manual member and therefore the operation of the fuel supply device, and means 0perated by the control pressure generator for selectively connecting the hydraulic pressure with said stop whereby said stop is eflective upon the vehicle reaching a predetermined speed, said selecting means including a plurality of independently selectable valves each operable to connect the hydraulic pressure with the stop upon the vehicle reaching a different speed.

13. In a speed control mechanism of the class described for internal combustion engines, the combination with a fuel supply device for con trolling the rate of supply of fuel to the engine and therefore the rate of travel of a vehicle driven by the engine, a manually operable member for operating the fuel supply device, and a hydraulic system for circulating a hydraulic fluid under pressure, of means for determining the ultimate desired speed of the vehicle comprising a control pressure generator driven by the engine and connected with the hydraulic system for modifying the pressure therein to control use, a hydraulic stop operated by the hydraulic fluid under pressure for limiting the operation of the manual member and therefore the operation of the fuel supply device, and means operated by the control pressure generator for selectively connecting the hydraulic pressure with said stop whereby said stop is effective upon the Vehicle reaching a predetermined speed, said selecting means including a plurality of independently selectable valves each operable to connect the hydraulic pressure with the stop upon the vehicle reaching a different speed, and means for selecting and indicating which of the valves is to be in operation and thereby preselecting the ultimate speed of the vehicle.

14. In a speed control mechanism of the class described for internal combustion engines the combination with a fuel supply device for controlling the rate of supply of fuel to the engine and therefore the rate of translation of a vehicle driven by the engine, a manually operable member for operating the fuel supply device, and a hydraulic system for circulating a hydraulic fluid under pressure, of means for determining the ultimate desired speed of the vehicle comprising a control pressure generator driven by the engine and connected with the hydraulic system of modifying the pressure therein to control use, a hydraulic stop operated by the hydraulic fluid under pressure for limiting the operation of the manual member and therefore the operation of the fuel supply device, means operated by the control pressure generator for selectively connecting the hydraulic pressure with said stop whereby said stop is effective upon the engine reaching a predetermined speed and thereby through the control pressure generator developing a predetermined control pressure, said selecting means including a plurality of in dependently selectable valves each operable to supply the required stop pressure to the hydraulic stop upon the engine reaching a difierent speed, said control pressure generator, generating two different pressures delivered simultaneously to the pressure selecting mechanism, and means operated simultaneously with the pressure selecting valve means for selecting the generated pressure desired.

15. A speed control device of the class described comprising a pressure generating mechanism driven from an internal combustion engine and at a rate of speed proportional thereto and including a pair of piston valves for respectively generating a different pressure but at a definite ratio one to the other regardless of the speed of operation of the generator or the engine, a hydraulic stop operable to limit the amount of fuel to be supplied to the engine and thereby limit and maintain the speed of rotation of the engine, and a pressure selecting and determining device between the pressure generating device and stop comprising a plurality of valves and a selector mechanism, a hydraulic fluid under pressure under control of said plurality of valves, said selector mechanism selecting which of the two pressures of the generating device is to be employed and which of the plurality of valves is to be operated to connect the hydraulic fluid to the hydraulic stop, and independent means for adjusting each valve to thereby require a different pressure for operating each valve with each of the generating pressures.

16. A speed control device of the class described comprising a pressure generating mechanism driven from an internal combustion engine and at a rate of speed proportional thereto and including a pair of piston valves for respectively generating a different pressure but at a definite ratio one to the other regardless of the speed of operation of the generator or the engine, a hydraulic stop operable to limit the amount of fuel to be supplied to the engine and thereby limit and maintain the speed of rotation of the engine, and a pressure selecting and determining device between the pressure generating device and stop comprising a plurality of valves and a selector mechanism, a hydraulic fluid under pressure under control of said plurality of valves, said selector mechanism selecting which of the two pressures of the generating device is to be employed and which of the plurality of valves is to be operated to connect the hydraulic fluid to the hydraulic stop, and independent means for adjusting each valve to thereby require a different pressure of operating each valve with each of the generating pressures and means for indicating which valve is selected and simultaneously indicating the speed of the vehicle at which the hydraulic stop will operate.

HAROLD A. BOWERS. 

